Exemplary embodiments herein relate to a tailgate for a motor vehicle. More particularly, the disclosure is related to a lightweight tailgate for a pick-up truck or like vehicle.
A conventional tailgate for a motor vehicle is formed from a number of steel sheets that are stamped and welded together. Sometimes, a steel reinforcement member is welded to the sheets to provide strength and rigidity to the tailgate. Latches are added on either side of the tailgate to engage a striker on the vehicle body (e.g., sides of a pick-up truck bed). A handle operates the latches to open and close the tailgate assembly. The steel tailgate can provide a durable and secure closure for the pickup bed. However, conventional tailgates generally do not have sufficient torsional stiffness and strength due, at least in part, to their reliance on a pair of full-time support cables extending from the lateral ends of the tailgate
Dual-mode tailgates are also generally known. “Dual-mode” refers to the two directions or pivot axes along which a dual-mode tailgate is openable. More particularly, a dual-mode tailgate is selectively openable in a first, fold-down direction about an axis generally parallel with a bottom edge of the tailgate similar to the conventional tailgate. The dual-mode tailgate is also selectively openable in a second, side-to-side direction about an axis generally parallel with a lateral edge of the tailgate. Known dual-mode tailgates cannot have a pair of full-time support cables extending from the lateral sides of the tailgate because the dual-mode tailgate needs to be able to swing open. To increase the torsional stiffness and strength of the dual-mode tailgate, it is known to form the tailgate from a stamped sheet metal frame having a reinforced cross-sectional shape.
These conventional tailgates have, however, certain disadvantages. For instance, the tooling and stamping equipment required to manufacture the tailgates from steel is expensive. Steel is also vulnerable to corrosion upon prolonged exposure to certain environmental conditions, which detracts from the appearance of the tailgate. In addition, the use of steel results in a heavy tailgate that is, for some individuals, difficult to open and close. For example, conventional tailgate can weigh between 30 and 40 pounds. Such a heavy tailgate also adds to the overall weight of the motor vehicle, which unnecessarily increases fuel consumption and wear on the vehicle.
Consequently, thermoplastic polymer panels have been incorporated into the conventional tailgates in an attempt to reduce their weight. However, merely substituting plastic components for the steel inner and outer panels of existing tailgate designs do not provide sufficient strength to meet load requirements. The plastic panels provide reduced strength and rigidity compared with steel panels. Further, the plastic panels can flex under normal loads and provide only limited torsional resistance.
A lightweight, durable tailgate is provided that is sufficient torsionally stiff and string such that it can be optionally supported with only a single support cable when in the fold-down position.